U.S. patent number 10,065,090 [Application Number 15/583,180] was granted by the patent office on 2018-09-04 for advanced hybrid iron type golf club.
This patent grant is currently assigned to TAYLOR MADE GOLF COMPANY, INC. The grantee listed for this patent is Taylor Made Golf Company, Inc. Invention is credited to Michael Guerrette, Tim Reed, Clive Roberts.
United States Patent |
10,065,090 |
Guerrette , et al. |
September 4, 2018 |
Advanced hybrid iron type golf club
Abstract
The present invention is a unique advanced hybrid iron type golf
club having a curved face. The golf club incorporates the discovery
of unique relationships among key club head engineering variables
such as volume, blade length, heel blade length section, Zcg,
front-to-back dimension, and club moment arm.
Inventors: |
Guerrette; Michael (Fairview,
TX), Reed; Tim (McKinney, TX), Roberts; Clive (Allen,
TX) |
Applicant: |
Name |
City |
State |
Country |
Type |
Taylor Made Golf Company, Inc |
Carlsbad |
CA |
US |
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Assignee: |
TAYLOR MADE GOLF COMPANY, INC
(Carlsbad, CA)
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Family
ID: |
42784973 |
Appl.
No.: |
15/583,180 |
Filed: |
May 1, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170232313 A1 |
Aug 17, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14226899 |
Mar 27, 2014 |
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12412493 |
May 20, 2014 |
8727909 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A63B
53/047 (20130101); A63B 53/0475 (20130101); A63B
53/0412 (20200801); A63B 53/0466 (20130101); A63B
53/0408 (20200801) |
Current International
Class: |
A63B
53/00 (20150101); A63B 53/04 (20150101) |
Field of
Search: |
;473/345,331,330,349,324 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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H11244429 |
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Sep 1999 |
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JP |
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2000342721 |
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Dec 2000 |
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JP |
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2001231888 |
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Aug 2001 |
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JP |
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Other References
Excerpts from Golf Digest; magazine; Feb. 2004; Article entitled:
"The Hot List", cover page from magazine and article on pp. 82-88.
cited by applicant .
Excerpts from Golf Digest; magazine; Feb. 2005; Article entitled:
"The Hot List", cover page from magazine and article on pp.
119-130. (Part 1). cited by applicant .
Excerpts from Golf Digest; magazine; Feb. 2005; Article entitled:
"The Hot List", article on pp. 131-143. (Part 2). cited by
applicant .
Excerpts from Golf Digest; magazine; Feb. 2006; Article entitled:
"The Hot List", cover page from magazine and article on pp.
122-132. (Part 1). cited by applicant .
Excerpts from Golf Digest; magazine; Feb. 2006; Article entitled:
"The Hot List", article on pp. 133-143. (Part 2). cited by
applicant .
Excerpts from Golf Digest; magazine; Feb. 2007; Article entitled:
"The Hot List", cover page from magazine and article on pp.
130-151. cited by applicant .
Excerpts from Golf Digest; magazine; Feb. 2008; Article entitled:
"The Hot List", cover page from magazine and article on pp.
114-139. cited by applicant .
Excerpts from Golf Digest; magazine; Feb. 2009; Article entitled:
"The Hot List", cover page from magazine and article on pp.
101-127. cited by applicant .
Nakahara, Aug. 2001, JP 200-231888, Human Translation, pp. 1-15.
cited by applicant .
Machine translation of IMAI--JP 11244429. cited by applicant .
Kajita, Dec. 2000, JP 2000-342721 A, Machine Translation, pp. 1-5.
cited by applicant .
Nakahara Aug. 2001, JP 2001-231888, Machine Translation, pp. 1-5.
cited by applicant.
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Primary Examiner: Kim; Gene
Assistant Examiner: Stanczak; Matthew B
Attorney, Agent or Firm: Dawsey co., LPA Dawsey; David
J.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. nonprovisional
application Ser. No. 14/226,899, filed on Mar. 27, 2014, which is a
continuation of U.S. nonprovisional application Ser. No.
12/412,493, now U.S. Pat. No. 8,727,909, filed on Mar. 27, 2009,
all of which is incorporated by reference as if completely written
herein.
Claims
We claim:
1. An advanced hybrid iron type golf club comprising: (a) a shaft
having a proximal end and a distal end; (b) a grip attached to the
shaft proximal end; and (c) a golf club head having (i) a curved
face positioned at a front portion of the golf club head where the
golf club head impacts a golf ball, wherein the face has a loft of
at least 15 degrees and no more than 42.5 degrees, and wherein the
face includes an engineered impact point; (ii) a sole positioned at
a bottom portion of the golf club head; (iii) a crown positioned at
a top portion of the golf club head; (iv) a skirt positioned around
a portion of a periphery of the golf club head between the sole and
the crown, wherein the face, sole, crown, and skirt define an outer
shell that further defines a head volume that is at least 40 cubic
centimeters and less than 100 cubic centimeters, and wherein the
golf club head has a rear portion opposite the face; (v) a bore
having a center that defines a shaft axis which intersects with a
horizontal ground plane to define an origin point, wherein the bore
is located at a heel side of the golf club head and receives the
shaft distal end for attachment to the golf club head, and wherein
a toe side of the golf club head is located opposite of the heel
side; (vi) a blade length measured horizontally from the origin
point toward the toe side of the golf club head a distance that is
parallel to the ground plane to the most distant point on the golf
club head in this direction, wherein the golf club head has a
front-to-back dimension that is no more than 65% of the blade
length and the blade length is at least 3.2 inches, and the blade
length includes: (a) a heel blade length section measured in the
same direction as the blade length from the origin point to the
engineered impact point; the heel blade length section is at least
1.2 inches; and (b) a toe blade length section; (vii) a club head
mass of at least 225 grams; (viii) a center of gravity located: (a)
vertically toward the top portion of the golf club head from the
origin point a distance Ycg; (b) horizontally from the origin point
toward the toe side of the golf club head a distance Xcg that is
generally parallel to the face and the ground plane; and (c) a
distance Zcg from the origin toward the rear portion in a direction
generally orthogonal to the vertical direction used to measure Ycg
and generally orthogonal to the horizontal direction used to
measure Xcg, wherein Zcg is 0.5 inches or less; (ix) a club moment
arm, within in imaginary impact vertical plane passing through the
engineered impact point and extending in a Z-direction, from a
horizontally translated projection of the CG on the imaginary
impact vertical plane to the engineered impact point; and (x) a
center face progression measured in the Z-direction, parallel to
the ground plane, from the engineered impact point to a vertical
plane through the shaft axis; (d) wherein the golf club has a club
length of at least 36 inches and no more than 42 inches.
2. The advanced hybrid iron type golf club of claim 1, wherein Zcg
is 0.4 inches or less.
3. The advanced hybrid iron type golf club of claim 1, wherein the
center face progression is no greater than 0.2 inches.
4. The advanced hybrid iron type golf club of claim 3, wherein the
heel blade length section is at least 1.3 inches.
5. The advanced hybrid iron type golf club of claim 1, wherein the
golf club head has a transfer distance that is a horizontal
distance from the CG to an imaginary vertical line extending from
the origin, and the transfer distance is at least 80 percent
greater than the club moment arm.
6. The advanced hybrid iron type golf club of claim 5, wherein the
transfer distance is no more than 125 percent greater than the club
moment arm.
7. The advanced hybrid iron type golf club of claim 1, wherein the
golf club head has a toe extreme distance measured from the CG to a
most distant point on the surface of the golf club head on the toe
side of the golf club head, and a ratio of the toe extreme distance
to the club moment arm is at least 2.15.
8. The advanced hybrid iron type golf club of claim 1, wherein a
ratio of the club moment arm to the heel blade length section is
less than 0.50.
9. The advanced hybrid iron type golf club of claim 8, wherein the
ratio of the club moment arm to the heel blade length section is at
least 0.40.
10. The advanced hybrid iron type golf club of claim 1, and a ratio
of the heel blade length section to the blade length is at least
0.40.
11. An advanced hybrid iron type golf club comprising: (a) a shaft
having a proximal end and a distal end; (b) a grip attached to the
shaft proximal end; and (c) a golf club head having (i) a curved
face positioned at a front portion of the golf club head where the
golf club head impacts a golf ball, wherein the face has a loft of
at least 15 degrees and no more than 42.5 degrees, and wherein the
face includes an engineered impact point; (ii) a sole positioned at
a bottom portion of the golf club head; (iii) a crown positioned at
a top portion of the golf club head; (iv) a skirt positioned around
a portion of a periphery of the golf club head between the sole and
the crown, wherein the face, sole, crown, and skirt define an outer
shell that further defines a head volume, and wherein the golf club
head has a rear portion opposite the face; (v) a bore having a
center that defines a shaft axis which intersects with a horizontal
ground plane to define an origin point, wherein the bore is located
at a heel side of the golf club head and receives the shaft distal
end for attachment to the golf club head, and wherein a toe side of
the golf club head is located opposite of the heel side; (vi) a
blade length measured horizontally from the origin point toward the
toe side of the golf club head a distance that is parallel to the
ground plane to the most distant point on the golf club head in
this direction, wherein the golf club head has a front-to-back
dimension that is no more than 65% of the blade length, and the
blade length includes: (a) a heel blade length section measured in
the same direction as the blade length from the origin point to the
engineered impact point, wherein a ratio of the heel blade length
section to the blade length is at least 0.40; and (b) a toe blade
length section; (vii) a club head mass of at least 225 grams;
(viii) a center of gravity located: (a) vertically toward the top
portion of the golf club head from the origin point a distance Ycg;
(b) horizontally from the origin point toward the toe side of the
golf club head a distance Xcg that is generally parallel to the
face and the ground plane; and (c) a distance Zcg from the origin
toward the rear portion in a direction generally orthogonal to the
vertical direction used to measure Ycg and generally orthogonal to
the horizontal direction used to measure Xcg, wherein Zcg is 0.5
inches or less; (ix) a club moment arm, within in imaginary impact
vertical plane passing through the engineered impact point and
extending in a Z-direction, from a horizontally translated
projection of the CG on the imaginary impact vertical plane to the
engineered impact point, wherein a ratio of the club moment arm to
the heel blade length section is less than 0.50; and (x) a center
face progression measured in the Z-direction, parallel to the
ground plane, from the engineered impact point to a vertical plane
through the shaft axis; (D) wherein the golf club has a club length
of at least 36 inches and no more than 42 inches.
12. The advanced hybrid iron type golf club of claim 11, wherein
the blade length is at least 3.2 inches, and Zcg is 0.4 inches or
less.
13. The advanced hybrid iron type golf club of claim 12, wherein
the heel blade length section is at least 1.2 inches, and the golf
club head has a transfer distance that is a horizontal distance
from the CG to an imaginary vertical line extending from the
origin, and the transfer distance is at least 80 percent greater
than the club moment arm.
14. The advanced hybrid iron type golf club of claim 13, wherein
and the heel blade length section is at least 1.3 inches, and the
center face progression is no greater than 0.2 inches.
15. The advanced hybrid iron type golf club of claim 11, wherein
the golf club head has a first toe projection distance measured
from a vertical projection of the engineered impact point on the
ground plane to a most distal point on a ground plane projection of
the extreme perimeter of the golf club head, and a ratio of the
first toe projection distance to the front-to-back dimension that
is at least 0.8.
16. An advanced hybrid iron type golf club comprising: (a) a shaft
having a proximal end and a distal end; (b) a grip attached to the
shaft proximal end; and (c) a golf club head having (i) a curved
face positioned at a front portion of the golf club head where the
golf club head impacts a golf ball, wherein the face has a loft of
at least 15 degrees and no more than 42.5 degrees, and wherein the
face includes an engineered impact point; (ii) a sole positioned at
a bottom portion of the golf club head; (iii) a crown positioned at
a top portion of the golf club head; (iv) a skirt positioned around
a portion of a periphery of the golf club head between the sole and
the crown, wherein the face, sole, crown, and skirt define an outer
shell that further defines a head volume, and wherein the golf club
head has a rear portion opposite the face; (v) a bore having a
center that defines a shaft axis which intersects with a horizontal
ground plane to define an origin point, wherein the bore is located
at a heel side of the golf club head and receives the shaft distal
end for attachment to the golf club head, and wherein a toe side of
the golf club head is located opposite of the heel side; (vi) a
blade length measured horizontally from the origin point toward the
toe side of the golf club head a distance that is parallel to the
ground plane to the most distant point on the golf club head in
this direction, wherein the golf club head has a front-to-back
dimension that is no more than 65% of the blade length the blade
length is at least 3.2 inches, and the blade length includes: (a) a
heel blade length section measured in the same direction as the
blade length from the origin point to the engineered impact point,
wherein the heel blade length section is at least 1.2 inches; and
(b) a toe blade length section; (vii) a club head mass of at least
225 grams; (viii) a center of gravity located: (a) vertically
toward the top portion of the golf club head from the origin point
a distance Ycg; (b) horizontally from the origin point toward the
toe side of the golf club head a distance Xcg that is generally
parallel to the face and the ground plane; and (c) a distance Zcg
from the origin toward the rear portion in a direction generally
orthogonal to the vertical direction used to measure Ycg and
generally orthogonal to the horizontal direction used to measure
Xcg, wherein Zcg is 0.4 inches or less; (ix) a club moment arm,
within in imaginary impact vertical plane passing through the
engineered impact point and extending in a Z-direction, from a
horizontally translated projection of the CG on the imaginary
impact vertical plane to the engineered impact point; and (x) a
center face progression measured in the Z-direction, parallel to
the ground plane, from the engineered impact point to a vertical
plane through the shaft axis; (d) wherein the golf club has a club
length of at least 36 inches and no more than 42 inches.
17. The advanced hybrid iron type golf club of claim 16, wherein
the heel blade length section is at least 1.3 inches.
18. The advanced hybrid iron type golf club of claim 16, wherein a
first moment of inertia (MOIy) about a vertical axis through the CG
is at least 2650 g*cm.sup.2.
19. The advanced hybrid iron type golf club of claim 16, wherein a
portion of the club head is formed of non-metallic material.
Description
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was not made as part of a federally sponsored
research or development project.
TECHNICAL FIELD
The present invention relates to the field of golf clubs, namely
hybrid iron type golf clubs. The present invention is a hybrid iron
type golf club characterized by a long blade length with a long
heel blade length section, while having a small club moment
arm.
BACKGROUND OF THE INVENTION
Hybrid iron type golf clubs have become widely accepted by amateur
golfers in the past decade, however more skilled golfers and
professional golfers have been somewhat reluctant to replace their
long irons with hybrid irons. These skilled golfers recognize the
significant increase in forgiveness offered by hybrid irons, yet
often complain that hybrid irons make it more difficult to work the
ball and control the trajectory. Such complaints may be warranted
because many hybrid irons are designed to fit into the game
improvement (GI) category of golf clubs, or even the super game
improvement (SGI) category of golf clubs. The attributes of such GI
and SGI hybrid irons that help amateur golfers get the ball
airborne with low lofted hybrid irons often reduce the playability
of such clubs in the hands of skilled golfers. Skilled golfers have
long needed hybrid irons designed specifically for their playing
abilities.
SUMMARY OF INVENTION
In its most general configuration, the present invention advances
the state of the art with a variety of new capabilities and
overcomes many of the shortcomings of prior methods in new and
novel ways. In its most general sense, the present invention
overcomes the shortcomings and limitations of the prior art in any
of a number of generally effective configurations.
The present advanced hybrid iron type golf club is characterized by
a long blade length with a long heel blade length section, while
having a small club moment arm, Zcg, and volume, while producing a
club head with a high moment of inertia. The golf club incorporates
the discovery of unique relationships among key club head
engineering variables that are inconsistent with merely striving to
obtain a high moment of inertia using conventional golf club head
design wisdom.
BRIEF DESCRIPTION OF THE DRAWINGS
Without limiting the scope of the present invention as claimed
below and referring now to the drawings and figures:
FIG. 1 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 2 shows a top plan view of an embodiment of the golf club, not
to scale;
FIG. 3 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 4 shows a toe side elevation view of an embodiment of the golf
club, not to scale;
FIG. 5 shows a top plan view of an embodiment of the golf club, not
to scale;
FIG. 6 shows a toe side elevation view of an embodiment of the golf
club, not to scale;
FIG. 7 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 8 shows a toe side elevation view of an embodiment of the golf
club, not to scale;
FIG. 9 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 10 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 11 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 12 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 13 shows a top plan view of an embodiment of the golf club,
not to scale;
FIG. 14 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 15 shows a top plan view of an embodiment of the golf club,
not to scale;
FIG. 16 shows a top plan view of an embodiment of the golf club,
not to scale;
FIG. 17 shows a step-wise progression of an embodiment of the golf
club as it approaches the impact with a golf ball during a golf
swing, not to scale;
FIG. 18 shows a step-wise progression of an embodiment of the golf
club head as it approaches the impact with a golf ball during a
golf swing, not to scale;
FIG. 19 shows a step-wise progression of an embodiment of the golf
club head as it approaches the impact with a golf ball during a
golf swing, not to scale;
FIG. 20 shows a top plan view of an embodiment of the golf club,
not to scale;
FIG. 21 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 22 shows a toe side elevation view of an embodiment of the
golf club, not to scale;
FIG. 23 shows a perspective view of an embodiment of the golf club,
not to scale;
FIG. 24 shows a perspective view of an embodiment of the golf club,
not to scale;
FIG. 25 shows a front elevation view of an embodiment of the golf
club, not to scale;
FIG. 26 shows a top plan view of an embodiment of the golf club,
not to scale;
FIG. 27 shows a top plan view of an embodiment of the golf club,
not to scale; and
FIG. 28 shows a table of data for currently available prior art
hybrid iron type golf club heads.
DETAILED DESCRIPTION OF THE INVENTION
The advanced hybrid iron type golf club enables a significant
advance in the state of the art. The preferred embodiments of the
golf club accomplish this by new and novel designs that are
configured in unique and novel ways and which demonstrate
previously unavailable but preferred and desirable capabilities.
The description set forth below in connection with the drawings is
intended merely as a description of the presently preferred
embodiments of the golf club, and is not intended to represent the
only form in which the golf club may be constructed or utilized.
The description sets forth the designs, functions, means, and
methods of implementing the golf club in connection with the
illustrated embodiments. It is to be understood, however, that the
same or equivalent functions and features may be accomplished by
different embodiments that are also intended to be encompassed
within the spirit and scope of the golf club.
In order to fully appreciate the present golf club some common
terms must be defined for use herein. First, one of skill in the
art will know the meaning of "center of gravity," referred to
herein as CG, from an entry level course on the mechanics of
solids. With respect to wood-type golf clubs, which are generally
hollow and/or having non-uniform density, the CG is often thought
of as the intersection of all the balance points of the club head.
In other words, if you balance the head on the face and then on the
sole, the intersection of the two imaginary lines passing straight
through the balance points would define the point referred to as
the CG.
It is helpful to establish a coordinate system to identify and
discuss the location of the CG. In order to establish this
coordinate system one must first identify a ground plane (GP) and a
shaft axis (SA). First, the ground plane (GP) is the horizontal
plane upon which a golf club head rests, as seen best in a front
elevation view of a golf club head looking at the face of the golf
club head, as seen in FIG. 1. Secondly, the shaft axis (SA) is the
axis of a bore in the golf club head that is designed to receive a
shaft. Some golf club heads have an external hosel that contains a
bore for receiving the shaft such that one skilled in the art can
easily appreciate the shaft axis (SA), while other "hosel-less"
golf clubs have an internal bore that receives the shaft that
nonetheless defines the shaft axis (SA). The shaft axis (SA) is
fixed by the design of the golf club head and is also illustrated
in FIG. 1.
Now, the intersection of the shaft axis (SA) with the ground plane
(GP) fixes an origin point, labeled "origin" in FIG. 1, for the
coordinate system. While it is common knowledge in the industry, it
is worth noting that the right side of the club head seen in FIG.
1, the side nearest the bore in which the shaft attaches, is
referred to as the "heel" side of the golf club head; and the
opposite side, the left side in FIG. 1, is referred to as the "toe"
side of the golf club head. The "heel" side and "toe" side are also
clearly identified in FIG. 27. Additionally, the portion of the
golf club head that actually strikes a golf ball is referred to as
the face of the golf club head and is commonly referred to as the
front of the golf club head; whereas, the opposite end of the golf
club head is referred to as the rear of the golf club head and/or
the trailing edge.
A three dimensional coordinate system may now be established from
the origin with the Y-direction being the vertical direction from
the origin; the X-direction being the horizontal direction
perpendicular to the Y-direction and wherein the X-direction is
parallel to the face of the golf club head in the natural resting
position, also known as the design position; and the Z-direction is
perpendicular to the X-direction, wherein the Z-direction is the
direction toward the rear of the golf club head. The X, Y, and Z
directions are noted on a coordinate system symbol in FIG. 1. It
should be noted that this coordinate system is contrary to the
traditional right-hand rule coordinate system; however, it is
preferred so that the center of gravity may be referred to as
having all positive coordinates.
Now, with the origin and coordinate system defined, the terms that
define the location of the CG may be explained. One skilled in the
art will appreciate that the CG of a hollow golf club head, such as
the advanced hybrid iron type golf club head illustrated in FIG. 2,
will be behind the face of the golf club head. The distance behind
the origin that the CG is located is referred to as Zcg, as seen in
FIG. 2. Similarly, the distance above the origin that the CG is
located is referred to as Ycg, as seen in FIG. 3. Lastly, the
horizontal distance from the origin that the CG is located is
referred to as Xcg, also seen in FIG. 3. Therefore, the location of
the CG may be easily identified by reference to Xcg, Ycg, and
Zcg.
The moment of inertia of the golf club head is a key ingredient in
the playability of the club. Again, one skilled in the art will
understand what is meant by moment of inertia with respect to golf
club heads; however, it is helpful to define two moment of inertia
components that will be commonly referred to herein. First, MOIx is
the moment of inertia of the golf club head around an axis through
the CG, parallel to the X-axis, labeled in FIG. 4. MOIx is the
moment of inertia of the golf club head that resists lofting and
delofting moments induced by ball strikes that are high or low on
the face. Secondly, MOIy is the moment of the inertia of the golf
club head around an axis through the CG, parallel to the Y-axis,
labeled in FIG. 5. MOIy is the moment of inertia of the golf club
head that resists opening and closing moments induced by ball
strikes towards the toe side or heel side of the face.
Continuing with the definitions of key golf club head dimensions,
the "front-to-back" dimension, referred to as the FB dimension, is
the distance from the furthest forward point at the leading edge of
the golf club head to the furthest rearward point at the rear of
the golf club head, i.e. the trailing edge, as seen in FIG. 6. The
"heel-to-toe" dimension, referred to as the HT dimension, is the
distance from the point on the surface of the club head on the toe
side that is furthest from the origin in the X-direction to the
point on the surface of the golf club head on the heel side that is
0.875'' above the ground plane and furthest from the origin in the
negative X-direction, as seen in FIG. 7.
A key location on the golf club face is an engineered impact point
(EIP). The engineered impact point (EIP) is important in that it
helps define several other key attributes of the present golf club.
The engineered impact point (EIP) is generally thought of as the
point on the face that is the ideal point at which to strike the
golf ball. The score lines on golf club heads enable one to easily
identify the engineered impact point (EIP) for any golf club. For
club heads with normal score lines, such as the embodiment of FIG.
9, the engineered impact point (EIP) is specifically defined and
identified by the following stepwise procedure. The first step in
identifying the engineered impact point (EIP) is to identify the
top score line (TSL) and the bottom score line (BSL). Next, draw an
imaginary line (IL) from the midpoint of the top score line (TSL)
to the midpoint of the bottom score line (BSL). This imaginary line
(IL) will often not be vertical since many score line designs are
angled upward toward the toe when the club is in the natural
position. Next, as seen in FIG. 10, the club must be rotated so
that the top score line (TSL) and the bottom score line (BSL) are
parallel with the ground plane (GP), which also means that the
imaginary line (IL) will now be vertical. In this position, a
leading edge height (LEH) and a top edge height (TEH) are measured
from the ground plane (GP). Next, a face height is determined by
subtracting the leading edge height (LEH) from the top edge height
(TEH). The face height is then divided in half and added to the
leading edge height (LEH) to yield the height of the engineered
impact point (EIP). Continuing with the club head in the position
of FIG. 10, a spot is marked on the imaginary line (IL) at the
height above the ground plane (GP) that was just calculated. This
spot is the engineered impact point (EIP).
The engineered impact point (EIP) may also be easily determined for
club heads having alternative score line configurations. For club
heads with alternative score lines, such as the golf club head of
FIG. 11 that does not have a centered top score line the engineered
impact point (EIP) is specifically defined and identified by the
following stepwise procedure. In such a situation, the two
outermost score lines that have lengths within 5% of one another
are used as the top score line (TSL) and the bottom score line
(BSL). The process for determining the location of the engineered
impact point (EIP) on the face is then determined as outlined
above. Further, some golf club heads have non-continuous score
lines. In this case, a line is extended across the break between
the two top score line sections to create a continuous top score
line (TSL). The newly created continuous top score line (TSL) is
then bisected and used to locate the imaginary line (IL). Again,
the process for determining the location of the engineered impact
point (EIP) on the face is then determined as outlined above.
The engineered impact point (EIP) may also be easily determined in
the rare case of a golf club head having an asymmetric score line
pattern, or no score lines at all. In such embodiments, the
engineered impact point (EIP) is specifically defined and
identified by the stepwise procedure set forth in the USGA
"Procedure for Measuring the Flexibility of a Golf Clubhead,"
Revision 2.0, Mar. 25, 2005, which is incorporated herein by
reference. This USGA procedure identifies a process for determining
the impact location on the face of a golf club that is to be
tested, also referred therein as the face center. The USGA
procedure utilizes a template that is placed on the face of the
golf club to determine the face center. In these limited cases of
asymmetric score line patterns, or no score lines at all, this USGA
face center shall be the engineered impact point (EIP) that is
referenced throughout this application.
The engineered impact point (EIP) on the face is an important
reference to define other attributes of the present invention. The
engineered impact point (EIP) is generally shown on the face with
rotated crosshairs labeled EIP.
One important dimension that utilizes the engineered impact point
(EIP) is a center face progression (CFP), seen in FIGS. 8 and 13.
The center face progression (CFP) is specifically defined as a
single dimension measurement that is the distance in the
Z-direction from the shaft axis (SA) to the engineered impact point
(EIP). A second dimension that utilizes the engineered impact point
(EIP) is referred to as a club moment arm (CMA). The CMA is
specifically defined as a two dimensional distance from the CG of
the club head to the engineered impact point (EIP) on the face, as
seen in FIG. 8. Thus, with reference to the coordinate system shown
in FIG. 1, the club moment arm (CMA) includes a component in the
Z-direction and a component in the Y-direction, but ignores any
difference in the X-direction between the CG and the engineered
impact point (EIP). Thus, the club moment arm (CMA) can be thought
of in terms of an impact vertical plane passing through the
engineered impact point (EIP) and extending in the Z-direction.
First, one would translate the CG horizontally in the X-direction
until it hits the impact vertical plane. Then, the club moment arm
(CMA) would be the distance from the projection of the CG on the
impact vertical plane to the engineered impact point (EIP). The
club moment arm (CMA) has a significant impact on the launch angle
and the spin of the golf ball upon impact.
Another important dimension in golf club design is the club head
blade length (BL), seen in FIG. 12 and FIG. 13. The blade length
(BL) is specifically defined as the distance from the origin to a
point on the surface of the club head on the toe side that is
furthest from the origin in the X-direction. The blade length (BL)
is composed of two sections, namely the heel blade length section
(Abl) and the toe blade length section (Bbl). The point of
delineation between these two sections is the engineered impact
point (EIP), or more appropriately, a vertical line, referred to as
a face centerline (FC), extending through the engineered impact
point (EIP), as seen in FIG. 13, when the golf club head is in the
normal resting position, also referred to as the design
position.
Further, several additional dimensions are helpful in understanding
the location of the CG with respect to other points that are
essential in golf club engineering. First, a CG angle (CGA) is the
one dimensional angle between a line connecting the CG to the
origin and an extension of the shaft axis (SA), as seen in FIG. 13.
The CG angle (CGA) is measured solely in the X-Z plane and
therefore does not account for the elevation change between the CG
and the origin, which is best understood with reference to the top
plan view of FIG. 13.
A dimension referred to as CG1, seen in FIG. 14, is most easily
understood by identifying two planes through the golf club head, as
seen in FIGS. 23 and 24. First, a shaft axis plane (SAP) is a plane
through the shaft axis (SA) that extends from the face to the rear
portion of the golf club head in the Z-direction. Next, a second
plane, referred to as the translated shaft axis plane (TSAP), is a
plane parallel to the shaft axis plane (SAP) but passing through
the GC. Thus, in FIGS. 23 and 24, the translated shaft axis plane
(TSAP) may be thought of as a copy of the shaft axis plane (SAP)
that has been slid toward the toe until it hits the CG. Now, the
CG1 dimension is the shortest distance from the CG to the shaft
axis plane (SAP). A second dimension referred to as CG2, seen in
FIG. 15, is the shortest distance from the CG to origin point, thus
taking into account elevation changes in the Y-direction.
Lastly, another important dimension in quantifying the present
invention only takes into consideration two dimensions and is
referred to as a transfer distance (TD), seen in FIG. 16. The
transfer distance (TD) is the horizontal distance from the CG to a
vertical line extending from the origin; thus, the transfer
distance (TD) ignores the height of the CG, or Ycg. Thus, using the
Pythagorean Theorem from simple geometry, the transfer distance
(TD) is the hypotenuse of a right triangle with a first leg being
Xcg and the second leg being Zcg.
The transfer distance (TD) is significant in that is helps define
another moment of inertia value that is significant to the present
invention. This new moment of inertia value is defined as a face
closing moment of inertia, referred to as MOIfc, which is the
horizontally translated (no change in Y-direction elevation)
version of MOIy around a vertical axis that passes through the
origin. MOIfc is calculated by adding MOIy to the product of the
club head mass and the transfer distance (TD) squared. Thus,
MOIfc=MOIy+(mass*(TD).sup.2)
The face closing moment (MOIfc) is important because is represents
the resistance that a golfer feels during a swing when trying to
bring the club face back to a square position for impact with the
golf ball. In other words, as the golf swing returns the golf club
head to its original position to impact the golf ball, the face
begins closing with the goal of being square at impact with the
golf ball. For instance, the figures of FIGS. 17(A), (B), (C), and
(D) illustrate the face of the golf club head closing during the
downswing in preparation for impact with the golf ball. This
stepwise closing of the face is also illustrated in FIGS. 18 and
19. The significance of the face closing moment (MOIfc) will be
explained later herein.
The present advanced hybrid iron type golf club has a shape and
mass distribution unlike prior hybrid iron type golf clubs. The
advanced hybrid iron type golf club includes a shaft (200) having a
proximal end (210) and a distal end (220); a grip (300) attached to
the shaft proximal end (210); and a golf club head (100) attached
at the shaft distal end (220), as seen in FIG. 25. The overall
advanced hybrid iron type golf club has a club length of at least
36 inches and no more than 42 inches, as measured in accordance
with USGA guidelines.
The golf club head (100) itself is a hollow structure that includes
a face positioned at a front portion of the golf club head where
the golf club head impacts a golf ball, a sole positioned at a
bottom portion of the golf club head, a crown positioned at a top
portion of the golf club head, and a skirt positioned around a
portion of a periphery of the golf club head between the sole and
the crown. The face, sole, crown, and skirt define an outer shell
that further defines a head volume that is at least 40 cubic
centimeters and less than 100 cubic centimeters for the present
invention. Additionally, the golf club head has a rear portion
opposite the face. The rear portion includes the trailing edge of
the golf club, as is understood by one with skill in the art. The
face has a loft of at least 15 degrees and no more than 42.5
degrees, and the face includes an engineered impact point (EIP) as
defined above. One skilled in the art will appreciate that the
skirt may be significant at some areas of the golf club head and
virtually nonexistent at other areas; particularly at the rear
portion of the golf club head where it is not uncommon for it to
appear that the crown simply wraps around and becomes the sole.
The golf club head (100) includes a bore having a center that
defines a shaft axis (SA) that intersects with a horizontal ground
plane (GP) to define an origin point, as previously explained. The
bore is located at a heel side of the golf club head and receives
the shaft distal end for attachment to the golf club head. The golf
club head (100) also has a toe side located opposite of the heel
side, as labeled in FIG. 27. The golf club head (100) has a club
head mass of at least 225 grams, which combined with the previously
disclosed loft, club head volume, and club length establish that
the present invention is directed to a hybrid iron type golf club,
also referred to as iron-woods, rescue irons, or simply,
hybrids.
As previously explained, the golf club head (100) has a blade
length (BL) that is measured horizontally from the origin point
toward the toe side of the golf club head a distance that is
generally parallel to the face and the ground plane (GP) to the
most distant point on the golf club head in the toe direction. The
golf club head (100) has a blade length (BL) of at least 3.2
inches. Further, the blade length (BL) includes a heel blade length
section (Abl) and a toe blade length section (Bbl). The heel blade
length section (Abl) is measured in the same direction as the blade
length (BL) from the origin point to the engineered impact point
(EIP), and in the present golf club, the heel blade length section
(Abl) is at least 1.2 inches. As will be subsequently explained,
the blade length (BL) and the heel blade length section (Abl) of
the golf club are unique to the field of hybrid iron type golf
clubs, particularly when combined with the disclosure below
regarding the relatively small club moment arm (CMA), high MOIy,
small Zcg, small front-to-back dimension (FB), and small center
face progression (CFP).
The golf club head (100) has a center of gravity (CG) located (a)
vertically toward the top portion of the golf club head from the
origin point a distance Ycg; (b) horizontally from the origin point
toward the toe side of the golf club head a distance Xcg that is
generally parallel to the face and the ground plane (GP); and (c) a
distance Zcg from the origin toward the rear portion in a direction
generally orthogonal to the vertical direction used to measure Ycg
and generally orthogonal to the horizontal direction used to
measure Xcg.
The present golf club head (100) has a club moment arm (CMA) from
the CG to the engineered impact point (EIP) of less than 0.625
inches. The definition of the club moment arm (CMA) and engineered
impact point (EIP) have been disclosed in great detail above and
therefore will not be repeated here. This is particularly
significant when contrasted with the fact that the present
invention has a first moment of inertia (MOIy) about a vertical
axis through the CG of at least 2650 g*cm.sup.2, which is high in
the field of hybrid iron type golf clubs directed to skilled
golfers or so-called "players" clubs, as well as the blade length
(BL) and heel blade length section (Abl) characteristics previously
explained. In fact, this unique relationship found in the present
invention has not been found in the prior art, as illustrated by
the table of FIG. 28, which contains product data for a broad
selection of current hybrid iron type golf clubs.
Achieving the right combination of design variables and ranges
found in the advanced hybrid iron type golf club that result in the
feel and ball flight that more highly skilled golfers prefer is a
difficult process. Controlling the club moment arm (CMA) while
attempting to increase the MOIy and maintain or reduce the club
head volume is important to achieve the performance desired by
skilled golfers. For instance, prior art products C and M of FIG.
28 are the only clubs in the table that have volumes of less than
100 cc, yet their club moment arms (CMA) and Zcg are larger than
desirable and their MOIy are less than desirable.
Prior art products N and O are the only clubs in FIG. 28 that have
a club moment arm (CMA) even close to the present golf club; yet
they are also characterized by less than desired MOIy values, and
larger than desired center face progression (CFP) values and
front-to-back dimensions (FB). Prior art product K illustrates what
generally happens as the MOIy value of a hybrid iron type golf club
increases; namely, the volume, Zcg, club moment arm (CMA), and
front-to-back dimension (FB) increase. These prior art products
fail to appreciate that a skilled golfer prefers the feel and
performance of a golf club having a long blade length (BL), a large
heel blade length section (Abl), a small club moment arm (CMA), a
small volume, and a relatively high MOIy; a unique balance of
seemingly unassociated variables that produces a particularly easy
to hit hybrid iron type golf club.
Prior art product K is particularly illustrative of common thinking
in club head engineering; namely, that to produce a high MOIy type
product, the club head must get large in all directions. However,
this results in a CG located far from the face of the club and thus
an undesirable club moment arm (CMA). The club moment arm (CMA) has
a significant impact on the ball flight of off-center hits.
Importantly, a shorter club moment arm (CMA) produces less
variation between shots hit at the engineered impact point (EIP)
and off-center hits. Thus, a golf ball struck near the heel or toe
of the present golf club will have launch conditions more similar
to a perfectly struck shot. Conversely, a golf ball struck near the
heel or toe of a conventional hybrid iron type golf club with a
large club moment arm (CMA), and short blade length (BL) and heel
blade length section (Abl), would have significantly different
launch conditions than a ball struck at the engineered impact point
(EIP) of the same hybrid iron type golf club, thus amplifying the
different ball flights of a well struck shot compared to a poorly
struck shot.
Generally, larger club moment arm (CMA) golf clubs impart higher
spin rates on the golf ball when perfectly struck in the engineered
impact point (EIP) and produce larger spin rate variations in
off-center hits. The present golf club's reduction of club moment
arm (CMA) while still obtaining a relatively high MOIy and the
desired minimum heel blade length section (Abl) is the opposite of
what prior art designs have attempted to achieve with hybrid iron
type golf clubs, and has resulted in an advanced hybrid iron type
golf club with more efficient launch conditions including a lower
ball spin rate per degree of launch angle, thus producing a longer
ball flight. As such, yet another embodiment of the advanced hybrid
iron type golf club has a club moment arm (CMA) of less than 0.6
inches, further capitalizing on the benefits of a small club moment
arm (CMA).
A common trend in hybrid iron type golf club design has been to
stick with smaller blade length (BL) club heads for more skilled
golfers. One basis for this has been to reduce the amount of ground
contact. Unfortunately, the smaller blade length (BL) results in a
reduced hitting area making these clubs difficult to hit. Thus, the
golf club's increase in blade length (BL) and the minimum heel
blade length section (Abl), while also having a relatively high
MOIy with a small club moment arm (CMA), all packaged in a low
volume club head, is unique. A further embodiment of the advanced
hybrid iron type golf club incorporates a minimum heel blade length
section (Abl) that is at least 1.3 inches, a value unseen by any of
the clubs in FIG. 28.
In addition to everything else, the prior art has failed to
identify the value in having a high MOIy hybrid iron type golf club
with an engineered impact point (EIP) located a significant
distance from the origin point. Conventional wisdom regarding
increasing the Zcg value to obtain club head performance has proved
unable to recognize that it is the club moment arm (CMA) that plays
a much more significant role in hybrid iron performance and ball
flight. Controlling the club moment arm (CMA) in the manner claimed
herein, along with the long blade length (BL), long heel blade
length section (Abl), while achieving a relatively high MOIy for
hybrid iron type golf clubs, yields launch conditions that vary
significantly less between perfect impacts and off-center impacts
than has been seen in the past. The present golf club provides the
penetrating ball flight that is desired with hybrid iron type golf
clubs via reducing the ball spin rate per degree of launch angle.
The present golf club has provided reductions in ball spin rate as
much as 5 percent or more, while maintaining the desired launch
angle. In fact, testing has shown that each hundredth of an inch
reduction in club moment arm (CMA) results in a reduction in ball
spin rate of up to 13.5 rpm.
As previously explained, more skilled golfers generally prefer
smaller volume hybrid iron type golf clubs. Another embodiment
capitalizes on this and incorporates a club head front-to-back
dimension (FB) that is 2.0 inches or less, which is significantly
less than a majority of the golf clubs in FIG. 28. Limiting the
club head front-to-back dimension (FB) makes it more difficult to
increase the MOIy. In still a further embodiment, the present golf
club head has recognized that discriminating skilled golfers prefer
a golf club head having a relatively large ratio of the heel blade
section (Abl) to the blade length (BL). An embodiment incorporates
a ratio of the heel blade section (Abl) to the blade length (BL)
that is at least 0.40, while still achieving the previously
described beneficial attributes.
Another significant performance and aesthetic indicator in hybrid
iron type golf clubs is the ratio of the club moment arm (CMA) to
the heel blade length section (Abl). In yet another embodiment of
the advanced hybrid iron type golf club, this ratio is less than
0.50. This ratio is a good measure of looks, playability, and feel,
and is not present in any of the clubs of FIG. 28, regardless of
club moment arm (CMA), size, or blade length (BL).
Another embodiment of the present golf club has recognized a unique
relationship of club moment arm (CMA) to heel blade length section
(Abl). High MOIy hybrid iron type golf clubs have failed to
appreciate the significance that the relationship between the club
moment arm (CMA) and the heel blade length section (Abl) has on the
ball launch conditions. Specifically, in this particular
embodiment, it was found that a ratio of the club moment arm (CMA)
to the heel blade length section (Abl) of less than 0.5 produced
preferred launch conditions for the advanced hybrid iron type golf
club of the present invention. Yet, simply minimizing the club
moment arm (CMA) is undesirable due to unstable ball flight
production, and producing an Abl that is too large is visually
unappealing. Thus, a further preferred range of this CMA to Abl
ratio is between 0.4 and 0.5 for advanced hybrid iron type golf
clubs.
Yet a further embodiment appreciates another previously
unrecognized relationship relevant to the performance of high MOIy
advanced hybrid iron type golf clubs. Simply increasing the MOIy or
reducing the club moment arm (CMA) is not the way to produce a
preferred hybrid iron type golf club. In addition to all the
previously described unique relationships, the present embodiment
of the golf club has recognized that there is a significant
relationship between the MOIy and the club moment arm (CMA). In
fact, in this embodiment, the ratio of the MOIy to the club moment
arm (CMA) should exceed 4500 g*cm.sup.2, thereby producing
preferred feel and playability.
In another embodiment, the golf club head front-to-back dimension
(FB) is less than 2.0, as seen in FIG. 20. The table of FIG. 28
illustrates that in the past, hybrid iron type golf clubs with high
MOIy values have generally elongated the club head in the front to
back direction, often resulting in less than desirable playability
due to excessive ground interaction and large CMA and Zcg values.
Conversely, the clubs that limit the front-to-back (FB), such as
prior art product M, have MOIy values over 10 percent less than the
present advanced hybrid iron type golf club. In this embodiment,
the limiting of the front-to-back dimension (FB) of the club head
(100) in relation to the blade length (BL) improves the playability
of the club, yet still achieves the desired high MOIy and small
club moment arm (CMA). The reduced front-to-back dimension (FB),
and associated reduced Zcg, of the present golf club also
significantly reduces dynamic lofting of the golf club head which
places the golf club head at a more advantageous position at
impact. Increasing the blade length (BL) of a hybrid iron type golf
club, while decreasing the front-to-back dimension (FB) and
incorporating the previously discussed characteristics with respect
to minimum MOIy, minimum heel blade length section (Abl), and
maximum club moment arm (CMA), simply goes against conventional
hybrid iron golf club head design and produces a golf club head
that has improved playability that would not be expected by one
practicing conventional design principles. Still a further
embodiment uniquely characterizes an embodiment of the present
advanced hybrid iron type golf club with a ratio of the heel blade
length section (Abl) to the blade length (BL) that is at least
0.40.
In the past, golf club design has made MOIy a priority.
Unfortunately, MOIy is solely an impact influencer. In other words,
MOIy represents the club head's resistance to twisting when a golf
ball is struck toward the toe side, or heel side, of the golf club.
The present golf club recognizes that a second moment of inertia,
referred to above as the face closing moment (MOIfc), also plays a
significant role in producing a golf club that is particularly
playable by even unskilled golfers. As previously explained, the
face closing moment of inertia (MOIfc) is the horizontally
translated (no change in Y-direction elevation) version of MOIy
around a vertical axis that passes through the origin. MOIfc is
calculated by adding MOIy to the product of the club head mass and
the transfer distance (TD) squared. Thus,
MOIfc=MOIy+(mass*(TD).sup.2)
The transfer distance (TD) in the equation above must be converted
into centimeters in order to obtain the desired MOI units of
g*cm.sup.2. The face closing moment (MOIfc) is important because is
represents the resistance felt by a golfer during a swing as the
golfer is attempting to return the club face to the square
position. While large MOIy golf clubs are good at resisting
twisting when off-center shots are hit, this does little good if
the golfer has difficulty consistently bringing the club back to a
square position during the swing. In other words, as the golf swing
returns the golf club head to its original position to impact the
golf ball the face begins closing with the goal of being square at
impact with the golf ball. As MOIy increases, it is often more
difficult for golfers to return the club face to the desired
position for impact with the ball. For instance, the figures of
FIGS. 17(A), (B), (C), and (D) illustrate the face of the golf club
head closing during the downswing in preparation for impact with
the golf ball. This stepwise closing of the face is also
illustrated in FIGS. 18 and 19.
Recently, golfers have become accustomed to high MOIy golf clubs,
particularly because of recent trends with modern drivers. In doing
so, golfers have trained themselves, and their swings, that the
extra resistance to closing the club face during a swing associated
with longer length golf clubs, i.e. high MOIy drivers, is the
"natural" feel of longer length golf clubs. Since golfers have
trained themselves that a certain resistance to closing the face of
a long club length golf club is the "natural" feel, one embodiment
of the present advanced hybrid iron type golf club has a face
closing moment (MOIfc) that is more in line with high MOIy drivers
resulting in a more natural feel in terms of the amount of effort
expended to return the club face to the square position; all the
while maintaining a short club moment arm (CMA). Skilled golfers
can perceive very fine changes and having a hybrid iron type golf
club that is much easier to return to the closed position than a
skilled golfer's driver or fairway woods can negatively influence
ones game. This more natural feel is achieved in the present
invention by increasing the face closing moment (MOIfc) to at least
5000 g*cm.sup.2.
In the previously discussed embodiment the transfer distance (TD)
is at least 1.2 inches. Thus, from the definition of the face
closing moment (MOIfc) it is clear that the transfer distance (TD)
plays a significant role in a hybrid iron type golf club's feel
during the golf swing such that a golfer squares the club face with
the same feel as when they are squaring their driver's club face;
yet the benefits afforded by increasing the transfer distance (TD),
while decreasing the club moment arm (CMA), have gone unrecognized
until the present invention.
A further embodiment of the previously described embodiment has
recognized highly beneficial club head performance regarding launch
conditions when the transfer distance (TD) is at least 80 percent
greater than the club moment arm (CMA). Even further, a
particularly effective range for advanced hybrid iron type golf
clubs has been found to be when the transfer distance (TD) is 80
percent to 125 percent greater than the club moment arm (CMA). This
range ensures a high face closing moment (MOIfc) such that bringing
the club head square at impact feels natural and takes advantage of
the beneficial impact characteristics associated with the short
club moment arm (CMA).
As previously mentioned, the present advanced hybrid iron type golf
club does not merely maximize MOIy, or minimize club moment arm
(CMA), because that would be short sighted. Increasing the MOIy
while obtaining the optimal balance of club moment arm (CMA),
volume, Zcg, blade length (BL), and heel blade length section (Abl)
involved identifying key relationships that contradict many
traditional golf club head engineering principles. This is
particularly true in the embodiment of the present golf club that
has the face closing moment (MOIfc) about a vertical axis through
the origin of at least 5000 g*cm.sup.2. Obtaining such a high face
closing moment (MOIfc), while maintaining a short club moment arm
(CMA), low volume, long blade length (BL), long heel blade length
section (Abl), and high MOIy involved recognizing key
relationships, and the associated impact on performance, not
previously exhibited.
All the ratios used in defining embodiments of the advanced hybrid
iron type golf club involve the discovery of unique relationships
among key club head engineering variables that are inconsistent
with merely striving to obtain a high MOIy using conventional golf
club head design wisdom. With the important relationships between
unnatural club head variables discovered, the implementation may be
accomplished in a number of ways. For instance, implementation may
include the use of multi-material club head construction, unique
club head geometry, and/or advanced club head weighting systems
that achieve the desired weight distribution and properties.
One embodiment of the present invention incorporates unique club
head geometry to obtain the previously described relationships
among the club head variables. As seen in FIG. 27, the present
embodiment includes a toe extreme distance (TED) measured from the
CG to the most distant point on the surface of the golf club head
on the toe side of the golf club head. The toe extreme distance
(TED) includes all three dimensions. In this configuration the
ratio of the toe extreme distance (TED) to the club moment arm
(CMA) is at least 2.15. A further embodiment also defines this
unique geometry via the introduction of a first toe projection
distance (TPD1), seen in FIG. 26, measured from the projection of
the engineered impact point (EIP) on the ground plane (GP) to the
most distant point on the perimeter of the ground plane (GP)
projection of the golf club head's top plan view perimeter. In
other words, when looking down on the crown of the golf club head,
the projection of the extreme perimeter of the club head, in this
view, on the ground plane (GP) establishes an outline on the ground
plane. Then, the most distant point on this ground plane outline
from the location of the projection of the engineered impact point
(EIP) on the ground plane (GP) can be identified. The distance
between these two points is the first toe projection distance
(TPD1); a dimension limited to the X-Z plane. In this particular
embodiment, the ratio of the first toe projection distance (TPD1)
to the club moment arm (CMA) is at least 1.90. Further, in yet
another embodiment, this ratio is obtained while maintaining a
front-to-back dimension (FB) that is less than 65 percent of the
blade length (BL). In still another embodiment, a second toe
projection distance (TPD2) further specifies a unique geometry that
achieves the desired relationships of the present golf club. The
second toe projection distance (TPD2) is measured from the origin
point to the most distant point on the perimeter of the ground
plane (GP) projection of golf club head's top plan view perimeter,
as previously explained. In this particular embodiment, the ratio
of the second toe projection distance (TPD2) to the club moment arm
(CMA) is at least 2.70. Still further, it is preferable to have a
ratio of the first toe projection distance (TPD1) to the
front-to-back dimension (FB) that is at least 0.8, and preferably
greater than 0.95; thus providing the playability of a high MOIy
long blade length hybrid iron type golf club, while guarding
against all the negatives characteristics associated with hybrid
irons having long front-to-back dimensions. Further, the embodiment
described with respect to FIGS. 26 and 27 allows selective
positioning of the discretionary mass of the advanced hybrid iron
type golf club head in an extreme position without extending the
head in the front-to-back direction.
The present advanced hybrid iron type golf club is not limited to
today's commonly available hybrid iron lofts of 15 degrees to 30
degrees. In fact, one embodiment of the present invention is
directed to higher lofted advanced hybrid iron golf clubs having
lofts ranging up to 42.5 degrees.
The various parts of the advanced hybrid iron type golf club head
may be made from any suitable or desired materials without
departing from the claimed club head, including conventional
metallic and nonmetallic materials known and used in the art, such
as steel (including stainless steel), titanium alloys, magnesium
alloys, aluminum alloys, carbon fiber composite materials, glass
fiber composite materials, carbon pre-preg materials, polymeric
materials, and the like. The various sections of the club head may
be produced in any suitable or desired manner without departing
from the claimed club head, including in conventional manners known
and used in the art, such as by casting, forging, molding (e.g.,
injection or blow molding), etc. The various sections may be held
together as a unitary structure in any suitable or desired manner,
including in conventional manners known and used in the art, such
as using mechanical connectors, adhesives, cements, welding,
brazing, soldering, bonding, and other known material joining
techniques. Additionally, the various sections of the golf club
head may be constructed from one or more individual pieces,
optionally pieces made from different materials having different
densities, without departing from the claimed club head.
Numerous alterations, modifications, and variations of the
preferred embodiments disclosed herein will be apparent to those
skilled in the art and they are all anticipated and contemplated to
be within the spirit and scope of the instant invention. Further,
although specific embodiments have been described in detail, those
with skill in the art will understand that the preceding
embodiments and variations can be modified to incorporate various
types of substitute and or additional or alternative materials,
relative arrangement of elements, and dimensional configurations.
Accordingly, even though only few variations of the present
invention are described herein, it is to be understood that the
practice of such additional modifications and variations and the
equivalents thereof, are within the spirit and scope of the
invention as defined in the following claims.
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